--- title: "21210 — Technical Specification" url: https://australianproperty.network/apn-codex/series-20000/series-21000/series-21200/21210-interest-rates/technical-specification/ date: 2026-07-03 modified: 2026-10-11 lang: en author: "Nicklas Clark" description: "APN Codex · Interest Rates (21210)Technical Specification Interest Rates (21210) — Technical Specification Published 3 July 2026 · Updated 30 September 2026 · Basis: certified parameters This page sets out..." word_count: 442 --- # 21210 — Technical Specification APN Codex · Interest Rates (21210)Technical Specification ### Interest Rates (21210) — Technical Specification Published 3 July 2026 · Updated 30 September 2026 · Basis: certified parameters This page sets out the full methodology behind Interest Rates (21210): vector construction, baseline parameters, composite aggregation, and the certification record. Where any prior research document conflicts with the figures below, the certified figures on this page are authoritative. #### Vector architecture | Vector | Series | Source | μ | σ | N | Weight | | ------ | ------ | ------ | --- | --- | --- | ------ | | Cash Rate Composite | 24 · RBA_OCR_CASH_RATE | RBA (daily, aggregated to a quarterly baseline observation) | 2.3558% | 1.4569 | 60 | 0.25 | | Retail Lending Rate | 25 · RBA_F5_INDICATOR_RATES | RBA F5 (monthly, aggregated to a quarterly baseline observation) | 6.2400% | 1.4270 | 60 | 0.25 | | 2-Yr Forward Yield Proxy | 26 · RBA_F2_YIELD_PROXY | RBA F2 (weekly, aggregated to a quarterly baseline observation) | 2.1319% | 1.2287 | 50 | 0.25 | | High-DTI Exposure | 27 · APRA_QPEX_HIGH_DTI | APRA Quarterly ADI Property Exposures (quarterly-native) | 12.5005% | 6.6380 | 28 | 0.25 | All four vectors are Tier-1 sovereign institutional sources; no commercial data dependency exists in the node. Under the A2 baseline-frequency pass ratified 15 August 2026, baseline μ/σ/N for the cash rate, retail lending rate and forward yield vectors are computed on the quarterly-resampled series (N = 60, 60 and 50 respectively) rather than on raw native-cadence observations — series 24 is ingested daily, series 25 monthly and series 26 weekly, each aggregated to one quarterly baseline observation. Series 27's certified sample (N = 28) is materially smaller than the other three vectors, reflecting APRA's quarterly-native publication cadence, and remains below the platform's minimum-observations threshold — a pre-existing, disclosed condition unrelated to this pass. #### Composite construction Certified Aggregation Method Zv,t = (Xv,t − μv) / σv  →  Z21210,t = Σ wv Zv,t over vectors present, w = 0.25 each Where a vector has no observation for a period, the composite is computed over the vectors present, with the coverage disclosed alongside the reading (four of four vectors present = full weighting). Missing observations are carried as NIL RETURN, never estimated or interpolated. #### Certification record | Reference period | Composite Z | Coverage | Status | Note | | ---------------- | ----------- | -------- | ------ | ---- | | Q4 2025 | +0.7057σ | 4 of 4 vectors | Certified 15 Jun 2026 | First formal certification for this node | | Q1 2026 | +1.0049σ | 4 of 4 vectors | Certified 15 Aug 2026 | Recertified under the A2 baseline-frequency pass (ratified 15 Aug 2026); supersedes a provisional pipeline reading of +1.0239σ certified 13 Jul 2026 under the prior native-cadence baseline | | Q2 2026 | +0.9807σ | 4 of 4 vectors | Certified 29 Sep 2026 | Position 96.6 against 30 full-coverage quarters from March 2019; the high-DTI baseline holds 28 observations, below the minimum-observations threshold, and is disclosed | #### Terminal observations (Mar 2026 vs Jun 2026, both certified) | Vector | Mar 2026 (certified) | Mar 2026 Z | Jun 2026 (certified) | Jun 2026 Z | | ------ | -------------------- | ---------- | -------------------- | ---------- | | Cash Rate Composite | 4.10% | +1.1972σ | 4.35% | +1.3688σ | | Retail Lending Rate | 8.52% | +1.5978σ | 8.77% | +1.7730σ | | 2-Yr Forward Yield | 4.803% | +2.1740σ | 4.406% | +1.8509σ | | High-DTI Exposure | 6.20% | −0.9494σ | 5.40% | −1.0697σ | Both columns use the quarterly-resampled baseline ratified on 15 August 2026. Certified rows are frozen historical records. The APN Academy distillation suite for this node carries references A-260703-C21210.1 through A-260703-C21210.6. [Parent nodeInterest Rates (21210) — Codex node page](https://australianproperty.network/apn-codex/series-20000/series-21000/series-21200/21210-interest-rates/)